The present invention relates to an article transporting facility including a single predetermined path disposed along a plurality of article transfer locations
and having opposed ends, a plurality of article transporting carriages traveling on the predetermined path, and a controller for controlling traveling of the predetermined number of article transporting carriages. Based on article transport request information for transporting an article from an original article transfer location to a destination article transfer location among the plurality of article transfer locations, the controller selects an article transporting carriage from the plurality of article transporting carriages for causing the selected carriage to transfer the article from the original article transfer location to the destination article transfer location.
The article transporting facility of the above-noted type is for use in e.g. an automated warehouse. In response to each article transport request information issued, the transporting operation of an article from an original article transfer location to a destination article transfer location is effected, and the facility effects such transporting operation one after another in repetition, with utilizing a plurality of article transporting carriages.
According to one known article transporting facility of the above-noted type, there are provided two article transporting carriages, and controlling means selects one of the two article transporting carriages for effecting an article transporting operation, based on transport request information (see, e.g. JP 2002-175117).
Referring more particularly to this conventional article transporting facility, adjacent each one of the opposed ends of the predetermined path, there is set an “allotted area” accessible by only predetermined one of the carriages. At the center area of the predetermined path, there is set a “shared area” accessible by both of the two carriages, but prohibiting simultaneous access by the two carriages. In operation, the controlling means selects one of the two article transporting carriages, depending on e.g. which of the opposed allotted areas the original article transfer location included in the transport request information is present.
With the above-described article transporting facility, by setting the allotted areas and the shared area, the article transfer locations accessible by each carriage are limited to some of the plurality of article transfer locations. On the other hand, there is also known an article transporting facility in which the article transporting carriages are accessible to all of the article transfer locations, without setting such allotted areas or shared area.
According to this conventional article transporting facility in which the article transporting carriages are rendered accessible to all the article transfer locations, the controlling means selects, from a plurality of article transporting cars, one particular carriage for effecting a requested article transporting operation, which particular carriage is located near the original article transfer location included in each transport request information.
Then, with this conventional article transporting facility, since the controlling means selects one particular carriage located near the original article transfer location included in the transport request information, depending on the situation of issuance of the article transport request information, it may happen that a same single article transporting carriage is selected repeatedly as the carriage for effecting a series of requested article transporting operations.
Therefore, in spite of the fact that a plurality of article transporting carriages are provided, the same single carriage may be used in repetition for effecting articles from transport starting article transfer location(s) to destination article transfer location(s). Thus, the facility fails to take advantage of utilization of the plurality of carriages, thus failing to improve transporting ability.
Referring more particularly to the above facility with reference to FIG. 1, a plurality of stations 1 as article transfer locations are arranged along the length of a predetermined path 2. As article transporting carriages, 3, two carriages, i.e. a first article transporting carriage 3a and a second article transporting carriage 3b are provided. These two carriages 3 can travel to/from, i.e. are accessible to all of the plural stations 1.
As an issuance situation of transport request information, it may happen that transport request information may issue in a plurality of times, which designate, among the plurality of stations 1, the station 1c located on the most left-side in FIG. 1 as the transport starting station. For instance, such situation tends to occur during certain hours when a great number of article retrieval operations from article storage shelves article or storage operations to the article storage shelves are carried out in a concentrated manner.
And, the transport starting station 1c designated in the transport request information is located close to the first article transporting carriage 3a of the first and second article transporting carriages 3a, 3b. Then, if the controlling means selects, from the two article transporting carriages 3, the one carriage located near the transport starting station 1c, the first article transporting carriage 3a will be selected repeatedly as the carriage for effecting the plurality of article transporting operations.
Hence, the first article transporting carriage 3a alone will be used repeatedly for transporting articles from the transport starting station to transport destination station(s), whereas the facility fails to utilize the second article transporting carriage 3b. 